Sex differences in coronary plaque burden and cardiovascular event risk revealed

Coronary artery disease (CAD) is the most common cause of death globally. In CAD, plaques composed of cholesterol, fats, calcium and other compounds accumulate and create obstructions in the coronary vessels that supply blood to the heart. It is well-known that plaque differs between women and men, with women typically having a smaller total volume of plaque, but it is unknown how this difference impacts risk of major adverse cardiovascular events (MACE). Investigators from Mass General Brigham analyzed data from nearly 4,300 stable outpatients with chest pain and no known prior CAD and found that, although women had smaller plaque volumes and fewer plaques with high-risk characteristics, they experienced similar rates of MACE compared with men and showed differences in how plaque burden related to cardiovascular risk over time. Results are published in Circulation.

Our findings suggest that applying uniform thresholds across sexes to determine whether patients' plaque measures put them at high risk for MACE may underestimate risk in women. Based on the apparent differences in risk trajectories between men and women, incorporating sex, and even age, into the interpretation of plaque metrics is an important next step toward more individualized risk assessment."

Jan Brendel, lead author of the Cardiovascular Imaging Research Center (CIRC), Mass General Brigham Department of Radiology

Investigators utilized data from the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE), which was conducted across 193 North American sites. Using cardiac computed tomography angiography (CCTA) images, the researchers measured total plaque volume and total plaque burden (TPB), which is the amount of plaque relative to the size of the blood vessel. They also characterized plaque subtypes, including stable plaques, which are harder and contain more calcium, and high-risk plaques, which are softer and contain more fat compounds.

After a median of 26 months, women's risk of MACE (death, heart attack or hospitalization for chest pain) was similar to men's. Although women had a lower median plaque volume than men, their vessel size-adjusted median TPB was similar. Importantly, risk of MACE emerged at a lower TPB in women: approximately 20% versus approximately 28% in men. Additionally, in women, risk of MACE increased more steeply at lower plaque burden levels, whereas in men, risk of MACE increased gradually, requiring larger amounts of plaque. The earlier, steeper risk of MACE in women persisted after adjusting for traditional risk factors, and other imaging findings including presence of high-risk plaques. These findings suggest that incorporating sex into the interpretation of coronary plaque metrics may help advance tailored approaches to cardiac risk stratification.